hello priyanka,

i know books are best for everything but in aptitude, you can go for online websites.because there are some websites which will let you to learn and practice if you didn't understand one type of method you can refer other method and explanation in dicussion forum.so its my suggestion only. decision is up to you.

Hi Priyanka,

Both are better than one another .RS Agarwal  is basic in nature and it will help you in basic and explain your concept effectively .

Arun Sharma and other books are for advanced studies...high level preparation

For Ability reasoning preparation RS Agarwal is the best one.

Thanks.